Flexon—the original memory metal frame—was developed more than 20 years ago. Made from a titanium nickel alloy, Flexon frames not only weigh a fraction of similarly designed frames, but they can also withstand most accidental, day-to-day mishaps. The secret to Flexon’s success is the material’s amazing flexibility. The bridge on most styles can repeatedly twist up to 90 degrees without breaking. Likewise, wrap most Flexon temples around a finger and they will spring back into shape.